MA Calculation

[Friend]

Dr. Ashby has documented Mechanical Advantage (MA) as the fourth highest penetration enhancing factor. Mechanical Advantage - BH MA ranks this high because it has a more pronounced influence on the outcome penetration of a perfectly flying and structurally sound arrow.

I am not questioning MA’s importance and influence but the actual calculation itself.
The following is a copy of a letter submitted to TuffHead since they capitalize on utilizing Dr. Ashby’s findings and provide a MA calculation sheet in promoting MA.

Subject: MA Length Measurement

Would believe that the actual measurement should start at the point and stop at the widest blade width point instead of the point where the blade tapers back to the ferrule.

While the Tuffhead value would still be quite formidable, MA calculations for the Silver Flame and the Eclipse Werewolf would most definitely be more accurately revealed as substantially inferior with regards to MA. The sweep backs from the max width blade point to the ferrule are significantly dramatic as compared to the TuffHead.
Note: The Sliver Flame relief width is ~2X and the Eclipse Werewolf is ~5 1/2X the relief width of the TuffHead. In my opinion, the MA calculations for the Silver Flame and Grizzly Werewolf would be highly exaggerated and could most errantly misdirect a consumer whom is basing their selection with regards to enhanced MA as a primary attribute.
 
Please see attachment.


Note: Click on 'X" for Trad Gang viewers
   


TuffHeads feedback would be highly appreciated.

Best regards,
Scott...aka 'Friend' on Trad Gang


The intent of this correspondence is in no way to promote one BH over another. Validity of the information conveyed is the objective.

I do not know anything about MA and do not understand what the pic behind the red X is explaining exactly, but I do know my scary sharp Silverflame XL's slide through critters like a hot knife through butter! The extra width of the XL generally gives me much better blood trail than ANY narrower 2 blade broadheads I have ever used, and I have used a bunch of different ones over the years.

Bisch

[Friend]

Mechanical Advantage is not some new convoluted idea generated for the more modern traditional archer. MA has been used in numerous common applications likely surfacing not long after the appearance of man.

The subject of this thread as previously posted is specifically not intended to serve as a catalyst to raise the defenses of individuals preferred head.  The subject of discussion is to specifically target MA calculations. Individual confidence should always remain a primary objective in an individual’s choice.

Mechanical Advantage
Dr Ed Ashby explains Mechanical Advantage of a broadhead this way:
“ The mechanical advantage of an inclined plane is equal to the length of the plane divided by the height of the plane. A single blade broadhead, with a straight taper, 1" wide by 3" long can be viewed as 2 inclined planes, each of which has a mechanical advantage of 6.0 (3" divided by 1/2"). The mechanical advantage of the two planes combined would be 3.0 because the height would be doubled while the length remains the same. What this means is that with an exerted force (effort) of 1 pound, a weight of 3 pounds can be lifted from the tip of the broadhead to the back edge of the broadhead. “
The higher the MA of a broadhead the more efficient it is in penetrating animal tissue and bone. The simple explanation for this is that a high MA broadhead generally has long cutting blades or surfaces which aid in cutting through soft and hard tissue. The width of the broadhead also contributes to penetration. Narrow broadheads show less resistance in bone increasing their penetration ability. The number of blades the broadhead has will have a big effect on MA .As the number of blades increase from two to three and four the MA is reduced significantly. This become more oblivious as one studies the simple formula for determining MA of a straight tapered broadhead. Substituting different measurements into the formula one can see how the length, width and number of blades of a broadhead affect the MA
 

To determine the mechanical advantage of any broadhead with a straight taper to the cutting edge, divide the horizontal length of the cutting blade by the width of the broadhead divided by 2 and multiplied by the number of blades. In an equation this would be expressed as:

M.A. = (Length of cutting blade) divided by (1/2 width of head) X (number of blades)
Using the TuffHead™ as an example- divide the cutting blade length (3.1875) by 1/2 of the overall width (which is 1.0625/2 or .53)then divide the result by the number of blades (which is 2 on the TuffHead) resulting in a (MA) mechanical advantage of 3.01

Hypothetically If the TuffHead had:

3 blades the MA = 2.00
4 blades the Ma = 1.50
It becomes obvious playing with the formula that by decreasing a broadhead’s length or increasing its’ width reduces its' MA. It is really obvious the more blades the broadhead has the less efficient it becomes.
Stated another way by Ed Ashby:
“The mechanical advantage equation dictates that the greater the length of a broadhead relative to the width, and the fewer the number of blades, the more efficiently it will be able to utilize the force applied to it.”

Click on ‘X’ for example

 

[L82HUNT]

Couple things we have unlimited doe tags where I hunt killing 5 a year is norm.  All hunting is done on private land where the deer are not spooky.  Deer where shot with a few different bows and arr
  MA to me means a lot less likey for a deer to bolt and run full out


I've shot somewhere near a dozen deer with the standard size silverflame and 1 elk.  Out if that only 1 of them animals( a small doe) really didn't react to the shot  meaning she just kind of jumped and then stood there and fell over
  Now I haven't killed as many with a tuffhead, just 4.  But so far 2 of the 4 have had little reaction.   Both where big does and both did almost the same thing.  Jumped went ten yards, stopped and started looking around
  Now grizzly heads which are similar to the tuffheads in size I've killed 15-20 deer.  And have had somewhere near 30% with little to no reaction

[L82HUNT]

I can't edit my post cause the sites still not working with my iPhone


The higher MA takes less  umph to go thru flesh and bone. Compared to short and fat.  This is why I think I'm getting much better results